1. Field of the Invention
The present invention relates to an insertion portion mounted tool of an insertion instrument and an insertion system that include an expansion and retraction section which is provided to an outer circumference of an insertion portion of an insertion instrument to be inserted into a subject and which is configured expanded to be held by an inner wall of the subject.
2. Description of the Related Art
In recent years, insertion instruments to be inserted into a subject or an object, for example, endoscopes have been widely used in medical fields and industrial fields.
Endoscopes for use in medical fields are capable of observing an organ in a body cavity using an optical system provided in an insertion portion by the elongated insertion portion being inserted into the body cavity as a subject, and performing various kinds of treatment, as needed, through the use of a treatment instrument inserted into a treatment instrument channel provided in the endoscope.
In addition, endoscopes for use in industrial fields are capable of performing observation and inspection of a flaw, corrosion, and the like of a site to be inspected in an object using an optical system provided in an insertion portion by the elongated insertion portion being inserted into the object such as a jet engine, a piping of a factory, or the like.
A procedure is well-known in which an insertion portion is inserted into a subject and a site to be examined is treated by using a treatment instrument inserted into a channel in the insertion portion by moving the insertion portion in a longitudinal direction of the insertion portion (hereinafter, shortly referred to as longitudinal direction) while observing the site to be examined with an optical system.
For example, in endoscopes for use in medical fields, a procedure is well-known in which, in a state where an insertion portion is inserted into a body cavity and a tissue to be treated in the body cavity is observed with an optical system, a treatment instrument inserted in a channel is protruded forward in the longitudinal direction of the insertion portion (hereinafter shortly referred to as forward) from the distal end in the longitudinal direction of the insertion portion (hereinafter, shortly referred to as distal end), and thereafter the tissue to be treated is dissected and resected by using the treatment instrument by moving the insertion portion in the longitudinal direction.
As one example, endoscopic submucosal dissection (hereinafter, referred to as ESD) is well-known, in which, in the state where an insertion portion is inserted into a body cavity and a carcinoma tissue in the body cavity is observed with an optical system, a high-frequency electrocautery scalpel inserted into a channel is protruded forward from the distal end of the insertion portion, and thereafter the carcinoma tissue raised in advance by injecting specialized-purpose liquid is removed with the high-frequency electrocautery scalpel, by moving the insertion portion forward and backward in the longitudinal direction of the insertion portion (hereinafter, just referred to as forward and backward).
In addition, as another example, endoscopic mucosal resection (hereinafter, referred to as EMR) is well-known, in which, in the state where an insertion portion is inserted into a body cavity and a carcinoma tissue in the body cavity is observed with an optical system, a snare inserted into a channel is protruded forward from the distal end of the insertion portion to be hooked on the carcinoma tissue raised in advance by injecting specialized-purpose liquid, and thereafter the carcinoma tissue is removed by constricting the snare while applying high-frequency current to the snare.
Japanese Patent Application Laid-Open Publication No. 2013-85812 discloses a configuration of an endoscope system including an overtube as an insertion portion mounted tool in which an insertion portion is inserted so as to be movable forward and backward, the overtube including, on the outer circumference on the distal end side in the longitudinal direction thereof (hereinafter, just referred to as distal end side), a balloon as an expansion and retraction section which is expandable and contractible in a subject by an operation from outside of the subject and expanded to be held by the inner wall of the subject. With the endoscope system, the balloon is expanded to be held by the body wall in the subject after the overtube having been inserted into the subject together with the insertion portion, and thereby the position of the distal end side of the overtube is fixed, to prevent the position in the longitudinal direction and the outer circumferential direction of the distal end side of the insertion portion in the overtube from being largely displaced in the subject.
In addition, Japanese Patent Application Laid-Open Publication No. 2011-24829 discloses a configuration of an endoscope system in which a balloon as an insertion portion mounted tool is directly fixed to the outer circumference of the distal end side of the insertion portion, to prevent the position in the longitudinal direction and the outer circumferential direction of the distal end side of the insertion portion from being greatly displaced in the subject, through the use of the balloon.